Slush-pump valve



SLUSH- VALVE Filed Aug 1 40 Dec, 3" 1940.

Patented Dec. 3, 1940 UNITED STATES SLUSH-PUMP VALVE -Clarence White,Walnut Park, and Oliver B. Graham, Los Angeles, Calif., assignors to OilWell Manufacturing Corporation, Los Angeles, Calif., a corporation ofCalifornia Application August 1, 1940, Serial No. 349,140

4 Claims.

. This invention relates to check valves, and more particularly to anovel form of check valve suitable for use in a slush-pump valvestructure.

In drilling oil wells by the rotary method, it 6 is customary tocontinuously supply rotary mud under pressure to the rotating bitthrough the drill pipe. A slush pump is utilized for developing thishigh pressure, The intake and outlet valves of the slush pump are of thecheck'valve type and ordinarily comprise a stationary seat with apressure-operated valve member adapted to seat thereon to form a fluidtight fit when the pressure on one side of the valve becomes greaterthan on the other side thereof by a predetermined amount.

The mud used in ordinary drilling operations contains large quantitiesof abrasive matter, which quickly wears away the valve and the valveseat.

A flexible rubber valve, because of its ability to conform to a roughseat wouldbe the most satisfactory form of valve for slush pumps if itwere not for the high pressure to which such a valve is subjected. Anall-metal valve, while capable of sustaining these high pressures, wearsrapidly under the abrasive action of the pumping fluids.

Valve structures combining metal and rubber parts to secure both theflexibility and resistance to high pressure have been devised for use inslush pumps. Such a valve structure is shown in Patent No, 2,103,503issued December 28, 1937, to one of the instant inventors. The inventionherein described is an improvement upon the valve structure describedin'the specification and shown in the drawing of that patent.

It is one object of this invention to provide a flexible sealing discfor use in a valve structure numbered patent which shall have both the avalve construction of the type of the above numbered patent in which thevalve and valve seat are so shaped in cross-sectional contour as to ofthe type shown and described in the above provide an effective sealingengagement between them when the valve is seated and at the same timepresent surfaces to the moving fluid so related to each other and to thedirection of flow of the fluid as to reduce to a minimum abrasivewearand deformation of the valve, valve seat and sealing disc and toprolong the life of the parts of the valve structure.

These and other objects of this invention will be understood from thefollowing description and claims in connection with the accompanyingdrawing, which presents the particular embodiments of the invention forillustrative purposes only.

In the drawing:

v Fig. 1 is a utility View illustrating a slush pump equipped with checkvalves embodying the features of my invention.

Fig. 2 is a sectional view of one of the check valves, showing the valve-in closed position,

Fig. 3 is an enlarged fragmentary-sectional view of portions of thesealing disc, valve, and valve seat.

Fig. 4 is a sectional view taken as indicated by the line 4-4 of Fig. 2.

Fig. 5 is a fragmentary cross-sectional view similar to Fig. 2 showinganother form of this invention.

Fig. 6 is ,a fragmentary sectional view similar to Fig, 2 of stillanother modified form of this invention.

Fig. 1 illustrates a slush pump generally designated by the numeral I0having a prime mover i l operatively connected by a connecting rod l2 toa pump section 33, The prime mover reciprocates the rod I2 which carrieswith it a piston l5 slidable in a liner Hi. This liner provides acylinder I! which is open at both ends, so as to communicate both withthe valve outlet passages IS' and I9 respectively and through two checkvalves (not shown) with the intake pipe 2|.

Two outlet or discharge valves 30 are disposed in two upwardly divergingtapered passages 32 formed in a valve deck 22. The passages 32 connectthe passages l8 and IS with a discharge passage 25. The two valvestructures 30 and the check valve structures (not shown) between theintake passage 2 I and the two ends of the cylinder I! are identical instructure, and are illustrated in Figs. 2 to 4 inclusive.

When the piston I5 is moved to the left the right-hand intake checkvalve (not shown) is opened by the pressure differential which existsbetween the intake passage 2i and the cylinder H and the valve of theright-hand valve structure 38 is held closed by the pressuredifferential-which exists between the discharge passage 25 and theoutlet valve passage l9, At the same time, the leftward intake valve(not shown) is held closed and the leftward check valve 38 is opened.Mud fluid flows into the right-hand end of the cylinder I1 and is forcedfrom the left-hand end of the cylinder through the valve outlet passagel8, liquid valve 38, and discharge passage 25.

When the direction of movement of the connecting rod I2 is reversed mudfluid flows from the inlet pipe 2| to the leftward chamber of thecylinder l1 and from the rightward chamber of the cylinder l1 throughthe rightward valve structure 38 to the discharge passage 25.

As is shown in Fig. 2, the valve deck 22 is provided with an upwardlydiverging tapered passage 32 adapted to receive a tapered metal valveseat 33, preferably in press-fit relationship therewith. The valve seat33 is provided with an upwardly facing, conical, centrally extending,lower seating surface 34 and a central hub 35 providing an axial bore35. The hub 35 is integrally connected to the body portion of the seatmember 33 by a web 31 substantially in the manner shown, so as toprovide a fluid passage 38 through the seat member.

Provided in a valve housing 28, directly above the valve structure 38,is an opening 48 of sumcient diameter to allow the passage of the valvestructure 38 therethrough. The opening 48 is closed by a suitable cap 4|having a centrally disposed depending cylindrical boss 45 formed with acentral cylindrical recess 42, which is interiorly threaded to receive athreaded bushing 43. This bushing has a central bore 44 which extendscoaxially with the bore 36 in the hub 35. A valve 58 has a. disc shapedbody 5| formed on its peripheral edge with a downwardly facing conicalfllseat 52 conforming to the shape of the seating surface.34 of the seat3 3. This body is designed to carry the pressure load on the valve. Thevalve body 5| has a preferably integral pin portion 53 l which projectsaxially both above and below the -valve disc or body 5|. The upperprojection of the pin constitutes a valve stem 55. These projections areof such diameters as to be slidably received in the bores 44 and 36respectively for the purpose of guiding the valve body 5| in its-vertical reciprocatory movements out of contact and into contact withthe valve seat 33. The boss 45 is formed with a plurality of radiallydisposed passages 55 therethrough adjacent the body of the cap 4| topermit free movement of mud fluid 55 into and out of a. bore chamber 45of the bushing 43 and thereby provide for a free sliding movement of thepin 53 within the bore 44.

Carried by the body portion 5| is a centrally apertured disc or annulus51 formed of hard rub- 60 her or other suitable material having bothlimited flexibility and sufflcient hardness to resist abrasion. The disc51 is preferably in the form of an annular ring which surrounds the stem55 and rests upon an upper surface 58 of the valve body 85 5|. This discis of larger diameter than the body 5| so as to extend outwardly beyondthe periphery thereof and preferably as far as the outer edge of anupper annular horizontal seating face 58 of the valve seat 33. 70Disposed on top of the disc 51 is a centrally apertured pressure plate88. Formed in the stem 55 and adjacent the pressure plate 68 is ashoulder 52 which forms the upper horizontal annular face of an annulargroove 53 formed in the stem 75 55. The shoulder 82 serves as anabutment for a resilient clip 18 adapted to retain in assembledrelationship the pressure plate 88, disc 51 and valve body 5|.

The clip 18 is in the form of a plate having a central opening 12 sizedto closely fit within the 5 annular groove 63 in the stem 55. The clipis provided with a pair of fingers 15 and 18 cooperating to form apassage 11 extending through one side of the plate to the centralopening 12.- As illustrated in Fig. 4, the width of a constricted 10portion 18 of this passage is slightly less than the diameter of thecentral opening 12. The outer portions of the fingers 15 and 16arepreferably tapered outwardly and beveled upwardly. Formed in the clip 18on the opposite side from the pas- 15 sage 11 is a cut out portion 8|communicating with the opening 12 in such a manner that the walls formedby the opening 12 provide a pair of arcuate segments 82 spaced as shownfrom the integral resilient portion adjoining the fingers 15 20 and 16.

With the disc 51 and the pressure plate 60 assembled on the valve .body5| as shown and previously described, the clip 18 is positioned on thepressure plate 60 so that the tapered surfaces 88 25 of the fingers 15and 16 engage the lower surface of the shoulder 62. The clip 18 is thendriven or otherwise forced laterally so that the fingers 15 and 16 snaparound the stem 55 into the position shown in Fig. 5, which serves toconfine the flexible disc 51 between the clip 18 and the body 5|.

It is obvious that for the removal of the disc 51 fromthe valve body, itis only necessary to force the clip 18 in the opposite direction to thatabove described whereupon the pressure plate 58 and the disc 51 may beremoved from the valve for replacement or for the purpose. of reversingthe valve disc 51.

By means of an upwardly extending annular rib 98 formed on the uppersurface 58 of the valve body 5|, and mating annular grooves 92 formed onopposite faces of the disc 51, the disc may be centralized with relationto the valves irrespective of that one of its two sides which is placeddownwardly.

Confined between the pressure plate 68 and the lower end of the boss 45is a compression spring 95 adapted to constantly urge the valve bodyinto engagement with the seat 33 against the pressure differential ofthe mud fluid in the fluid chambers on the two sides of the valvestructure.

In the operation of the valve, the valve body 5| carries the pressureload of the mud fluid above the valve and transmits it through theseating surfaces 52 and 34 to the valve seat 33, and a 55 radiallyoutermost annular portion 96 of the lower surface 91 of the insert disc51 engages the annularface 59 of the seat 33 forming an annular seal byreason of the relatively compressible character of the insert disc 51.60

The conical surfaces 34 and 52 do not extend all the way to the surfaces58 and 59, but terminate a relatively short distance therefrom. Thesurface 52-is connected to the surface 58 by a conical surface 86, whichforms with the axis line a:--:c of the valve structure (see Fig. 2) asmaller angle than that formed by the surface 52. The valve seat 33 isformed with a corresponding conical surface 85 inclined to the axis ofthe valve structure at the same angle as the surface 86 and conformingto that surface.

The valve body 5| and the valve seat 33 may be machined so that thesurfaces and 88 have a seating contact in the same manner as thesurfaces 34 and 52, or surfaces 85 and 86 may be 7'5 spaced a relativelysmall distance apart to present a' conical void 81. The surfaces 85 and86 need not necessarily be conical, but may be curvilinear or of otherdesign. It is essential to the principle of the invention, however, thatthe circle of intersection of these surfaces with the surfaces 58 and 59be greater than the circle of their intersection with the surfaces 34and 52, and less than the circle of intersection of the projection ofthe surfaces 34 and 52 with the surfaces 58 and 59.

These surfaces 85 and 88 present seating and sealing contact auxiliaryto that of the surfaces 34 and 52. This novel design possesses severaladvantages. If the surfaces 34 and 52 were extended to the surfaces 58and 59, the valve body 5| would have formed at the junction of thesurfaces 52 and 58 an annular feather edge which would curl upwardlyunder the heavy pressure of the 'mud fluid flowing upwardly between thesurfaces 34 and 52 as the valve is dropping toward the seat. Thisfeather edge would cut into the rubber material of the valve insert disc51. If to obviate this disadvantage the upper end of the surface 52 weremade cylindrical for a short distance, a void would be presented betweenthis cylindrical surface and the upper portion of the surface 34 intowhich the material of the disc insert 51 would protrude as the valvestructure is used, forming a ring of disintegrated sponge-' like rubberextending both into the void and above the void. This ring wouldeventually wear away, leaving an annular arcuate groove extendingupwardly into the disc insert 51 opposite the void. Such a grooveweakens the disc insert 51.

If on the other hand the upper portions of surfaces 34 and 52 are bothmade cylindrical in contacting conformance to avoid a void and toprevent the formation of a feather edge on the valve body 5|, the lowerannular edge of the cylindrical surface on the valve body 5| willstrike, chip, and wear away the upper annular edge of the cylindricalsurface on the valve seat 33 due to the radial play of the pin 53 in thebushing 43 and hub 35.

The surfaces 85 and 88 avoid all of these difficulties. The feather edgeon the valve body 5| is eliminated. The conical character of thesurfaces 85 and 86 takes care of the radial play of the valve body withrespect to the seat 33. The formation of a sponge rubber ring on theinsert disc 51 is entirely eliminated, if the surfaces 85 and 86 are incontactual seating relationship. If they are separated by a slight gapas shown in Fig. 3, this gap is soon reduced to zero by wear of thesurfaces 34 and 52 and is in any event too small to cause deteriorationin the juxtaposed portion of the under-surface 91 of the valve insert51. In addition, these two surfaces 85 and 86, being at an angle to thesurfaces 34 and 52, check the flow of mud fluid and increase the sealingeffect over that which would exist if the surfaces 34 and 52 wereextended all the way to the surfaces 58 and 59.

The insert disc 51 is made of non-metallic material of slightlycompressible character which is, however, sufficiently hard to resistthe blows to which it is subjected and the abrasive action of the mudfluid. It is preferably made of hard rubber, although it may be made ofBakelite or other non-metallic and plastic material.

While the disc 51 is more compressible than metal and has effectivesealing contact with the surface 59 of the valve seat. itsincompressibility makes it difficult to insert the clip 10 thereabove.

In Fig. 5 is shown a rubber ring or annulus 98, preferably of the samediameter as the superimposed pressure plate 68, which is inlaid eitherloosely or adhesively in the upper face of an insert disc 51a. Thisrubber ring 98 is of softer material than the insert disc 51a and byreason of its greater compressibility, facilitates the assembling of theseveral parts of the valve and the driving into place of the clip 10.

The ring 98 accomplishes another purpose. It softens the blow of theouter annular portion of the insert disc 51a on the valve seat 33, andof the valve body 5| on the surface 34 of the valve seat 33, lengtheningthe interval of time from the initial contact up to the instant at whichthe full pressure is developed between the contacting surfaces.Furthermore, as the surfaces 34 and 52 and surfaces 85 and 86 becomeworn in use, the upper surface 58 of the valve body 5| drops somewhatbelow the upper surface 59 of the valve seat 33. The rubber ring 98,after such wear has developed, prevents the development of full pressurebetween surfaces 59 and 96 at the time these two surfaces first contactas the valve is falling,. absorbs much of the energy of the blow as itis being compressed, delivers up this energy slowly to the falling valvestructure, most of the energy being finally delivered by the valve body5| to the seat 33 through the contact of surfaces 34 and 52, therebysparing the outer annular surface 96 of the valve insert 51a.

The rubber ring 98 need not necessarily be inlaid in the upper surfaceof the valve insert 51, as shown in Fig. 5, but may, as shown in. Fig.6, be incorporated as a soft rubber ring 98a between an upper and lowerlayer of the valve insert 515. The soft rubber ring may be inlaid in theundersurface of the valve insert 51, or in both the upper and undersurfaces thereof. A ring or lamina of soft rubber in any of thesedispositions facilitates the insertion of the clip 18, and lessens theblow of the valve insert upon the outer annular surface 59 of the valveseat, both when the valve structure is new and after a period of use.Furthermore, the reduction of the vertical crosssectional area of hardrubber in the valve insert at annular zones other than the extreme outerannular portion of the valve insert allows a downward flexure of theinner portion of the valve insert as the valve structure becomes worn,insuring a tight seal between the surfaces 59 and 96 and insuring thereception of the greater part of the impact of the valve on the valveseat at the surfaces 34 and 52, rather than between the surfaces 59 and96.

The term in juxtaposition as used herein to describe the relativeposition of two faces of the valve parts defines the two faces asdirected toward each other and includes both a position of actualcontact and a position of relatively slight separation of the two faces.

Although there have been herein described certain embodiments'of thisinvention, it is understood that various changes may be made and theinvention may be embodied in other structures without departing from thescope of the invention, which is defined in the appended claims.

Weclaim as our invention: Y

1. In a valve structure, the combination of a valve seat having anannular face perpendicular to the axis of said structure, a firstconical face flaring inwardly away from said annular face annular facesof both said valve seat and valve body respectively.

'2. In a valve structure, the combination of: a valve seat having anannular face perpendicular to the axis of said structure, a firstconical face flaring inwardly away from said annular face and a secondinwardly flaring conical face connecting said annular face and saidfirst conical face and forming a smaller angle with said axis than saidfirst conical face; a valve body having a first conical face conformingto and contacting said first conical face of said valve seat, a secondconical face conforming to and spaced a relatively small distance fromsaid second conical face on said valve seat, and an annular faceparallel to and substantially in the same plane as said annular face ofsaid valve seat; and a sealing disc having an annular face contactual-1y engaging said annular faces of both said valve seat and valve bodyrespectively.

3. In a valve structure, the combination of: a valve seat having anannular face perpendicular to the axis of said structure, a firstconical face flaring inwardly away from said annular face,. and a secondinwardly flaring conical face connecting said annular face and saidfirst conical face and forming a smaller angle with said axis than thefirst conical face; a valve body having a conical face parallel to andcontacting said first conical face of said valve seat, an annular faceparallel to and substantially in the same plane as said annular face ofsaid valve seat, and a face connecting said last-mentioned annular faceof said valve body and said first conical face of said valve body anddisposed opposite said second conical face of said valve seat; and asealing disc'having an annular face contactually engaging both saidannular face of said valve seat and said first mentioned annular face ofsaid valve body.

4. In a valve structure, the combination of a valve seat having anannular face perpendicular to vthe axis of said structure, a conicalvalve seat face tapering inwardly away from said annular face, and aface connecting said annular and valve seat faces and intersecting saidannular face in a circle greater than the circle of intersection of saidconnecting face and said valve seat face and smaller than the circle ofintersectionof the projection of said valve seat face with said annularface; a valve body having a conical face conforming to said valve seatface, an annular face parallel to and substantially in the same plane assaid annular face of said, valve seat, and a face connecting, saidconical face and annular face and conforming to said connecting face ofsaid valve seat; and a sealing disc having an annular face contactuallyengaging said annular faces of both said valve seat and valve bodyrespectively.

CLARENCE WHITE. OLIVER. B. GRAHAM.

